The NTSB has release its report including the probable cause of the January 16, 2006 accident in El Paso, TX in which a mechanic was ingested into an engine during a ground run to check for a possible oil leak. From the report:
 
“Witnesses on the ground and in the airplane stated that they saw the mechanic on the outboard side of the engine stand up, step into the inlet hazard zone, and become ingested into the intake of the engine. This occurred about 90 seconds into the 70-percent-power engine run. The mechanic was not wearing any type of safety equipment or lanyard to prevent the ingestion. Upon sensing a buffet, the captain immediately retarded the power lever back to the idle position. The first officer stated to the captain that something went into the engine and the captain immediately cut off the start lever to stop the engine run. The mechanic who was fatally injured was hired by the FBO in November 1997, and had been a certified mechanic for 40 years. He received maintenance training from the airline regarding on-call maintenance procedures in March 2004, nearly two years prior to the accident … Specific training (either initial or recurrent) regarding ground engine runs and associated hazards was not provided to the contract mechanics by the airline.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows: the mechanic's failure to maintain proper clearance with the engine intake during a jet engine run, and the failure of contract maintenance personnel to follow written procedures and directives contained in the airline's general maintenance manual. Factors contributing to the accident were the insufficient training provided to the contract mechanics by the airline, and the failure of the airport to disseminate a policy prohibiting ground engine runs above idle power in the terminal area.”
To review the entire report: